The main objectives of this research are to study neural mechanisms regulating ACTH and growth hormone (GH) secretion in the rat. Several projects will attempt to identify structures responsible for rhythmic and stress-induced ACTH secretion and for the feedback regulation of the pituitary-adrenal system. Other experiments will explore the control of growth and plasma GH levels; a major aim is to determine the neuroendocrine basis for augmented growth and plasma GH levels resulting from isolation of the medial basal hypothalamus. Related projects will study structures mediating stress-induced decreases in GH secretion. A final series of projects will focus on the neural basis for stress-induced alterations in prolactin and LH secretion.